Another embarrassment for anti-fluoride campaigners as neurotoxic claim found not to be justified

Anti-fluoride campaigners have made the classic mistake of promoting claims based on a draft report. Now peer reviewers have found the claim unjustified and the report will be rewritten. But will the anti-fluoride brigade stop making the claim?

Anti-fluoride campaigners have just lost another of their propaganda claims with the release of a US National Academies of Science (NAS) peer review of the recent National Toxicity Program’s (NTP) draft monograph discussing fluoride exposure and neurotoxicity.

Ever since the release of this draft last October anti-fluoride campaigners have been making hay out of this statement on page 2 of the draft (and repeated several times in its text):

“Conclusions: NTP concludes that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans.”

In general, these campaigners have presented this conclusion as a finding of the NTP, even though the draft includes this statement on every page:

“This DRAFT Monograph is distributed solely for the purpose of pre-dissemination peer review under the applicable information quality guidelines. It has not been formally disseminated by NTP. It does not represent and should not be construed to represent any NTP determination or policy.”

In a clear case of counting eggs before they hatch, the anti-fluoride campaigners now face the embarrassment of losing this claim because the NAS peer reviewers have found the conclusion is not supported by the evidence presented in the draft report. The NAS press release announcing the results of their peer review clearly says:

It “does not find that NTP has adequately supported its conclusion that “fluoride is presumed to be a cognitive neurodevelopmental hazard to humans.”

For readers wanting more detail these are the relevant documents:

Anti-fluoride activists response to the NAS peer review

The peer review has been out for only a few days and the anti-fluoride propagandists on social media have already denounced it (without reading it in most case) as only one committee’s opinion. Or they have indulged in the straw-clutching of quoting the NAS peer review’s sentence after the one that found the conclusion fo the NTP report was not supported. This says.

“The committee emphasized its finding does not mean that the NTP’s conclusion is incorrect; rather, further analysis or reanalysis is needed to support conclusions in the monograph.”

Perfectly normal for a scientific assessment and, in this case, a bit of a face-saver for the NTP (in many of its details the NAS peer review is quite scathing). And if the NTP has done a reasonable job of accessing the literature we all know that no “further analysis or reanalysis” will magically support the draft claim.

But, as an indication of the embarrassment of these people the “authoritative” comment on the peer review from Paul Connett, leader of the anti-fluoride US activist group Fluoride Action Network (FAN) almost reads like an endorsement of the peer review. Despite FAN having originally stressed the faulty NTP draft conclusion that “fluoride is presumed to be a cognitive neurodevelopmental hazard to humans” Connett does not even mention the NAS finding in his press release (see Federal report finding fluoride lowers IQ of children reviewed by National Academy of Sciences.“) Strangely he quotes: “The NAS emphasized its finding ‘… does not mean that the NTP’s conclusion is incorrect.'” without even saying what that conclusion was.

The rest of Connett’s comments amount to spin – putting a brave face on his disappointment at this major loss. His claim that “The NAS suggestions should strengthen the draft report’s conclusion that fluoride is a presumed neurotoxin in children” is fanciful given that the material reviewed by the NTP simply does not support this claim.

He is also attempting diversion with his claim “The NAS review has been misinterpreted by fluoridation defenders. The NAS did not independently review the scientific evidence but instead limited itself to comments on whether the NTP clearly and thoroughly explained their methods” The fact is very few comments have been made by “fluoridation defenders” yet – the peer review has been public for only a few days – barely enough time for busy scientists to get around to reading it. And I have not seen a single person claim that the NAS peer reviewers “independently reviewed the evidence.”

What was required of the peer review?

The peer review report makes their action and purpose very clear. They were not tasked with making an independent review of the literature but their job went a lot further than limiting themselves to “comments on whether the NTP clearly and thoroughly explained their methods”

The NTP Project Information document Peer Review of the NTP Monograph on Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects) provided a list of requirements for the peer reviewers who were asked to address the following questions:

  • Has the systematic review protocol been followed and modifications appropriately documented and justified?
  • Does the monograph accurately reflect the scientific literature?
  • Are the findings documented in a consistent, transparent, and credible way?
  • Are the report’s key messages and graphics clear and appropriate?  Specifically, do they reflect supporting evidence and communicate effectively?
  • Are the data and analyses handled in a competent manner?  Are statistical methods applied appropriately?
  • What other significant improvements, if any, might be made in the document?
  • Does the scientific evidence in the NTP Monograph support NTP’s hazard category conclusions for fluoride in children and adults?”

The NAS peer reviewers clearly answered the last question with an emphatic No! This is not changed by the desperate straw clutching of propagandists who quote the (inevitable and polite) qualification that a further “further analysis or reanalysis” might provide support. Nor is it changed by Connett simply refusing to acknowledge or comment on that very important finding of the peer review committee.

Other findings of the NAS peer reviewers

The NAS peer review report is quite extensive (it’s 48 pages long) and covers several other important issues besides its rejection of the main conclusion. Issues related to how good the original protocol was and how closely it was followed, bias resulting from incomplete consideration of all the findings (negative as well as positive) and selection in the literature considered, issues related to statistical analysis and presentation, and problems with accounting for the range of different fluoride exposure measures and outcome parameters.

I might return to some of these issues later as I think they are relevant to other reviews in this area – especially the recent review of Grandjean (2019) – Developmental fluoride neurotoxicity: an updated review. This has similar faults – and some extra faults of its own.

But it is clear that in it’s current form the draft NTP report is not credible. Its conclusion is flawed and there are a number of other problems. It will have to be extensively rewritten to take the peer reviewers comments into account. I look forward to the new, and hopefully much better, version.

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29 responses to “Another embarrassment for anti-fluoride campaigners as neurotoxic claim found not to be justified

  1. Steve Slott

    There is really no other way to put it……NAS ripped the NTP a new one for that shoddy mess NTP sent them for review. Connett was heavily banking on this report to use in his “lawsuit” and all his other propaganda campaigns. In spite of his desperate, comical attempts to spin this now, the steam is undoubtedly pouring out of the eyes and ears of his extremely red face with egg all over it.

    After months of enduring the shoddy, agenda-driven IQ and other studies churned out from the assembly line of Till and her followers, it is extremely nice to see a respected, independent source finally say “enough!” and put this nonsense into proper perspective. NTP should have known better than to put out such a report in the first place. NAS spanked them and sent them back to ground zero to start over and begin acting like responsible scientists rather than water carriers for FAN. Hopefully that panel has learned its lesson and will now provide a serious report sometime next year.

    Steven D. Slott, DDS


  2. Steve Slott

    Things will really get comical when Oz starts spinning his way into here.


  3. Bill – did you not read my article? I referred to Connett’s press release you quote. He was obviously embarrassed because he did not even refer to the main point that the NTP’s conclusion was not supported by the evidence – yet referred to the comment this ” . .does not mean that the NTP’s conclusion is incorrect.”

    You guys are all over the place at the moment you are so embarrassed.


  4. Yes, Oz is such a baby about this. However, I am keeping most of his comment in moderation at the moment because of slanderous comments he made about me (claiming I am receiving funds from “Russia” to promote a pro-fluoride message so as to lower the IQ of Americans, and also his claim I refused to proceed with an on-line good faith scientific exchange with me something he actually pulled out of]).

    If Tulsi Gabbard can take legal action against Clinton for such slander I think I can at least discipline him by refusing access until he withdraws and apologises.

    I may be forced to allow a comment of his through, though, if it makes a reasonable point. But don’t expect anything.


  5. Libel has no place here, Ken. I’m no fan of not publishing comments, but there is a line. You are fully justified in making him conform to acceptable standards before publishing his comments.

    Steven D. Slott, DDS


  6. Steve Slott

    Connett obviously believes that people will not read the NAS document. Judging from his ridiculous comments, it appears that he hasn’t read it himself.

    Steven D. Slott, DDS


  7. Steve Slott

    If and when Oz submits something printable, perhaps we should grade his spin on a Connett scale of absurdity……1 being rational to 10 being Connett. Although the selection was broad, one of Connett’s more hysterical statements was that:

    “ Many NAS suggestions are minor and should have little effect on the conclusion of ‘presumed’ neurotoxic in children.”

    This is akin to stating that many effects of the atomic bomb on Hiroshima were minor and would have little effect on their way of life….

    Steven D. Slott, DDS


  8. Be interesting to see if anything transpires about minority responses. I think the minority response of triggered schizoaffective disorder from cannabis may be starting to be more widely acknowledged.

    Sometimes coincidences could be more than just coincidence in minorities. I shall be interested in any links of fluoridation to spinal stenosis in minorities.


  9. Steve Slott

    Brian, you’re not seriously citing “fluoridealert” are you? What’s next, a reference to a Mickey Mouse comic book?

    Sigh….. let’s keep this discussion credible please

    Steven D. Slott, DDS


  10. Brian, as a conspiracy theorist you will also be fascinated by the attempt of a well-known Aussie anti-fluodidationist to link the Coronavirus to fluoride. After all, it originated in China and they have areas of endemic fluorosis. 🙂


  11. The ways they sideline investigation of minorities.


  12. Ken there also can be a conspiracy to put down minorities. Your coronavirus/fluoride example could easily be put out there as an easy thing to discredit, and take good thinkers down, too.


  13. A better conspiracy theory for the coronavirus seeding is the World Military Games which was held shortly before the coronavirus started to show and less than 20km away from the touted sea food market. I wonder how well all the nationalities’ luggage would have been searched.


  14. Ha, Ha. it is being promoted by Geoff Pain on Researchgate. With idiots like that there is no need for the pro-science side to indulge in such pettiness.

    Mind you the “links of fluoridation to spinal stenosis in minorities” may well be a plant.


  15. Ken wrote: “Mind you the “links of fluoridation to spinal stenosis in minorities” may well be a plant.”
    No a request for more input from me.

    Here something suggestive:

    Click to access NZSCIR-Annual-Technical-Report-2016-2017.pdf

    Where comparing spinal injuries treated in Auckland (fluoridated) with Canterbury (not-fluoridated) shows of the samples looked at, a greater proportion in the fluoridated area were non-traumatic. That means some other reason than traumatic injury is more prevalent in Auckland. Need to think of reasons.

    Brian Sandle


  16. Funny, Geoff Pain also presented his conspiracy theory as “a request for more input from me.”

    I wish you would comment on and discuss the article instead of opportunistically and selfishly using this space to push your conspiracy theories. That is very bad manners.


  17. Ken your link to the National Academies gives: “The National Academies report does not find that NTP has adequately supported its conclusion that “fluoride is presumed to be a cognitive neurodevelopmental hazard to humans.” The committee emphasized its finding does not mean that the NTP’s conclusion is incorrect; rather, further analysis or reanalysis is needed to support conclusions in the monograph.”

    So they are asking for more, too.
    There wouldn’t have to be a single cause effect for “neurotoxicity.”
    Note that it is being measured indirectly, through IQ &c.
    Pressure on the nerves of susceptible individuals, such as spinal stenosis, is affecting the nerves by reducing their blood supply. Neurotoxic? If one nerve happens to be squeezed the body’s resources must be taxed with less available for intellectual development?


  18. No, they are not asking for more – they simply point out that the conlcusion is not supported by the presented evidence.

    It is up to NTP. If they have unpresented evidecne then it should be included (but that is simply straw-clutching).

    The reasonable assessment is that the conclusion represents a bias. The report will have to be rewritten to amend or remove that conclusion.

    Mind you, the NAS review found a whole range of problems with the NTP report and I am guessing that it will be a while before the corrected version is available. If they take the advice of doing their own searching and translation of Chinese papers the job will be even bigger.


  19. No, soundhill, NAS isn’t asking for more. As Ken has pointed out, this committee was only charged with assessing whether NTP adequately supported its conclusion. It was not charged with addressing neurotoxicity of fluoride, with assessing stenosis, with assessing world peace, whether little green men from Mars have invaded the planet…..or anything else. In overwhelming manner, NAS said that NTP did not properly support its conclusion and sent them back to the drawing board to completely redo their report utilizing proper scientific methods and guidelines. In other words, the original monograph and its conclusions are worthless in terms of scientific validity.

    Assumedly, NTP will try again. This will entail putting together a new, far more credible monograph, putting it out for public comment, then resubmitting for proper review. If it provides a serious attempt this time which will actually bear up under scrutiny, it will probably be another year or so before the final report comes out.

    Steven D. Slott, DDS


  20. What is ” further analysis” if not more?


  21. Reanalysis or further analysis of the existing reviewed studies. There is the assumption that the NTP actually got all the studies.

    But you may be right. For example, despite their discussion of ADHD they completely ignored my paper:

    Perrott, K. W. (2018). Fluoridation and attention deficit hyperactivity disorder a critique of Malin and Till (2015). British Dental Journal, 223(11), 819–822.

    Ironic, as Grandjean who attempted to prevent publication of my paper did actually include it in his 2-19 review.

    Of course, my paper could not have been used to support their unwarranted conclusion. But their ignoring of it is relevant to the NAS peer reviewer’s comments about inadequate consideration of covariates and confounders:

    “the committee identified many cases in which NTP’s evaluation of confounding was insufficient, difficult to understand, or applied inconsistently across studies. NTP should develop clear criteria that are defined in the protocol to identify critical confounders and, if these are not consistently applied to individual studies, explain why some potential confounders are considered to be of greater importance in some studies and not others. NTP should also address critical aspects of confounding, such as magnitude and directionality”


  22. ““the committee identified many cases in which NTP’s evaluation of confounding was insufficient, difficult to understand, or applied inconsistently across studies.”
    Same in a fashion as I identified in the Broadbent paper the need to have specified nitrate levels in water which they didn’t as well as fluoride which they did.

    Canterbury District Health Board has cottoned on.

    When a kettle is left on a log burner it will evaporate down and concentrate nitrate in the water. Nitrate has a pathway in a baby which stops the baby from being able to transport oxygen in its blood. Some die maybe SIDS, some recover but damage may have occurred.

    The Tairei water can be quite high in nitrate. Presumably Tairei was one of the non-fluoridated experimental areas. Broadbent et al. have declined to say.

    Not fair to use such water as a control. It’s a bit like a “way in which Merck committed fraud in its Gardasil vaccine safety trials was by using a neurotoxic ingredient in Gardasil as a bioactive placebo. This trick effectively renders its safety testing null and void, as the true extent of harm cannot be ascertained.”


  23. There is no indication that nitrate would be a confounder in Broadbent’s study. In order to credible demand consideration of such, there must be valid evidence that there may be a concern.

    Steven D. Slott, DDS


  24. Brian, you “identified” nothing of the sort. You were simply straw-clutching to avoid the Broadbent et al (2015) findings. findings that are completely expected and similar to any other study of CWF throughout the world.

    Be a man and instead of speculating to support your straw clutching present the evidence. That is what I did with the Malin & Till (2015) study and proved it was flawed because it did not include important risk-modifying factors.

    Until you actually provide the evidecne – a full statistical analysis of the data – you are simply dishonestly straw-clutching.

    Meanwhile, you attempt to divert from the very important and very interesting subject I discussed in this article. I can appreciate that you are embarrassed that the anti-fluoride/anti-vaccination brigade has suffered a huge defeat (they had been promoting the false draft conclusion from NTP for months) – but surely it would be more honest to engage with the articles points, to enter into an honest discussion of these, than to attempt the diversions you have.


  25. Ken you want to close off the data and keep the “full statistical analysis” to that past stuff.
    So you are limiting confoundment sources.
    A new study gives:
    “Meta-analysis of eight studies assessing nitrate in drinking water and CRC supports a health benchmark of 0.14 mg/L.”

    I think they are talking nitrate-nitrogen which would be about 20% of the nitrate figure.

    As I sent to you some years back the nitrate levels in some wells on the outskirts of Dunedin can be over 5 mg/l.


  26. Ken Broadbent et al don’t reply to me. I don’t have access to their data to analyse.

    Already nearly 6 years ago I was this far:

    Brian R SANDLE Presentation to the Health Services Select sub committee on 23 March 2014 on the Health (Fluoridation of Drinking Water) Amendment Bill.
    This Bill does not encourage DHBs to consider costs of fluoridation other than the financial costs of installing and operating the equipment. If there be a cost to development of Intellectual Quotient in any part of its range or genetic variant I suggest that that could lessen New Zealand’s earning power or increase health costs.
    If there be a cost to rugby performance of top players, likewise.
    The Royal Society report based its IQ safety assertion on the Dunedin Study. Dunedin has more iodine in its water than Christchurch and Christchurch has had much more goitre than Dunedin. A study by Lin FF and others found that levels of water fluoride comparable to those used in fluoridation do have negative effect on IQ when children have low iodine intake. DHBs should be instructed to consider that.
    And I maintain that the Dunedin Study had a fault in that an unspecified portion of its non-fluoridated control group of 99 drank water from wells in Mosgiel which are high on nitrate. The level can be over 5 mg/litre which is 50 to 500 times that of much of Dunedin. Nitrate is known to affect the thyroid and iodine metabolism, and could have lost any advantage of the unfluoridated control group.
    Going to rugby: No All Black captains have been born in Auckland, our largest city, since fluoridation started there in 1966.
    Petone has always been an unfluoridated area of the Wellington region. Wellington’s top rugby players compete for the Jubilee Cup since 1929. Up until 1966 Petone won 23% of years. Then the rest of Wellington region but not Petone was fluoridated. Even though more teams came on the scene, from then on non-fluoridated Petone nearly doubled wins to 43%. of years. That is until Petone College closed and children had to cross the Hutt River and go to
    school in the fluoridated area. Petone club then dropped out of the Jubilee Cup to a lower grade.
    Timaru was fluoridated from 1973 to 1985, South Canterbury produced no more All Blacks after 1972 having produced 22 before that. It also dropped out of Division 1 rugby.
    More of the Hawke’s Bay Magpies are selected from the non-fluoridated areas of Hawkes Bay which however has similar size fluoridated and nonfluoridated populations
    Non-fluoridated Canterbury has done very well in rugby.
    Going to soccer: Starting about 8 years after fluoridation started in Birmingham in 1970, Birmingham have had no more wins in soccer with unfluoridated Manchester in a contest which has been going on for a long time.
    This Bill should encourage DHBs to be awake to other possible costs of fluoridation for their region than just the financial costs of installing and operating the equipment. What other deficits may be found for various abilities and impacted points in lives?
    I don’t think we are ready to lay down legislation which presumes fluoridation to be free of non-”financial” costs. When Broadbent and the Dunedin Study authors were challenged in a letter in the American Journal of Public Health they added that dental fluorosis is not found to be associated with IQ deficit. But they have not replied to me saying whether they are using the common meaning of the term “dental fluorosis” which may include other white opacities on teeth rather than just the ones caused by fluoride. More diffuse but symmetrical-in-the-mouth opacities are caused by fluoride. Were Broadbent’s assessors noting that difference in those years? Illnesses, medicines and other trauma can cause opacities, too. The opacities are caused by damage by fluoride or other trauma to the cells which make the tooth enamel. Is it so sure it won’t damage other cells: maybe especially those in people with common COMT gene variants?
    I note that our current All Black captain Kieran Read, who grew up in the non-fluoridated South of Auckland region of older Drury, got a sports scholarship to top school St Kentigerns in fluoridated Auckland but decided to return back to his home area. Could fluoridation have been one possibly unconscious factor there, that he didn’t feel he was doing so well in the fluoridated area?


  27. Scientists usually don’t reply to emails from nutters. But like other critics of the Broadbent study you could have made your critique to the publishing journal and got a response. Broadbent’s paper must be one of the most critiqued ones on this subject (all critiques from FAN people) and the authors responded to all those critiques which were published in the journal. The replies often included analysis of new data to satisfy the issues raised.

    But you are simply Gish galloping. Your comment on my article was extremely weak and several people showed that – now you attempt a diversion.

    Please stop that. It is disrespectful to use articles in this way.


  28. Brian, please stop personal attacks like this. I am not wanting “to close off the data and keep the “full statistical analysis” to that past stuff.” (Whatever that means).

    You have the freedom to do what other critics of the Broadbent study did – the fact you didn’t shows you are not serious.

    And it is simply a disrespectful diversion from my article to attempt to raise your personal obsessions here. Set up your own blog where you can present your conspiracy theories to your heart’s content – they aren’t welcome here.


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